Stock gauge for blast furnaces



Jan. 16, 1951 J. E. HEYWORTH ET AL STOCK GAUGE FOR BLAST FURNACES FiledAug. 21, 1947 YIIIIIIIIII.

' INVENTORS.

', JAMES ERIC HEYWORTH o EDWABDFRANCIS HARKINS.

Patented Jan. 16, 1951 STOCK GAUGE FOR BLAST FURNACES James EricHeyworth and Edward Francis Harkins, Cleveland, Ohio, assignors toRepublic Steel Corporation, Cleveland, Ohio, a corporation of New JerseyApplication August 21, 1947, Serial No. 769,924

Claim.

against the cables or rods and tend to erode or abrade them. Also, whencharging, the solid materials discharged from the charging hopper intothe furnace may strike and damage the gauge. Furthermore, the gauge mustbe capable of being moved up and down through the top of the furnace andyet must be sealed against the escape of gases. The problem of providinga satisfactcry stock gauge has always been present, even with furnacesoperating at conventional pressures, but is acute with furnacesoperating at higher than conventional pressures. In higher pressureoperations the pressure drop through the packing of the stock gauge isgreater than in conventional operations, and consequently gas escapingthrough the packing would flow more rapidly and cause substantially morethan normal erosion.

The present invention provides a stock gauge which has satisfactorilymet the conditions of high pressure furnace operation. Brieflydescribed, this gauge comprises a cable carrying a weight at its lowerend in the furnace and extending up through the top of the furnacewithin a tube. In its preferred form the cable is equipped with atubular protector consisting of, short lengths of pipe looselysurrounding the cable. Guides are positioned in the tube some distanceapart and substantially flll the space between the inner surface of thetube and the outer surface of the cable, or its tubular protector when aprotector is present. The tube is provided with an inlet between theguides for gases under greater pressure than that in the furnace. Thusthe flexible cable is protected against erosion and abrasion, the escapeof gas from the furnace is impeded by the guides and higher pressuregas, and the higher pressure greatly retards, if not prevents the entryof abrasive solids into the tube.

A better understanding of my invention will be gained by those skilledin the art upon consideration of the following detailed description andthe drawings accompanying and forming a part of this specification, inwhich Figure l is a fragmentary, side elevational view.

partly in section, of stock gauge assembly embodying one form of thisinvention;

Figure 2 is an enlarged fragmentary view of a portion of the gaugeassembly of Fig. 1 taken on line 2--2 of Fig. 3 and showing the gaspressure chamber; and

Figure 3 is a cross sectional view taken on line 3-3 of Fig. 2.

The present stock gauge comprises a cable III which is secured at oneend to a weight II to maintain constant tension in the cable, and at theother end to a winch (not shown) for raising and lowering the cable andweight to determine the stock level within a blast furnace. Asillustrated in Fig. 1, cable It extends vertically through dome I2 ofthe blast furnace and through an upright housing l'3 secured to the domeand fitted with a removable apertured closure plate l4 at its upper endoutside the furnace. Throughout most of its length, including that partnormally within the furnace, cable III is provided with protectingsleeves It made up of a plurality of short pipe sections which aresupported by a retaining ring l'l secured to cable l0 above the point ofattachment of weight ll. Above housing It, the cable and sleeves iii areenclosed in a vertically e rtending gas sealing chamber 20 through which.the cable and sleeves may move freely when determining the stock levelin the stack of the furnace.

Chamber 20 is defined by a tube 2| having open ends, and an opening atanintermediate point communicating through a pipe or conduit 23 with asource of gas under pressure (not shown). Two centrally apertured guidesor bushings 24 are welded to the ends of the tube 2|. An auxiliary pipe25 opens upwardly into tube 2| near the upper bushing.

The guides 24 are preferably of larger outside diameter than the tube2l', and the central apertures in these guides are flared outwardly sothat the ends of the tube 2| may be seated therein and welded to theguides, as shown in Fig. 2. Between the flared ends, the apertures areof slightly greater diameter than the outside diameter of sleeves It, sothat gas flow into or out of the chamber through the guides will beimpeded, yet will permit free vertical movement of the sleeves and cablethrough chamber 20. The lower guide 24 may be welded to plate l4, withthe apertures in the guide on the plate in register.

The lower guide or bushing 24 is provided with a plurality of, in thiscase three, passages 26 inclined downwardly therethrough and openinginto the central aperture thereof. Pipes 21 are welded 3 to the bushingand communicate with passages 28.

In the use of the illustrated device, gas is in- Jected continuouslythrough pipe 23 into chamber 20 at a predetermined pressure slightly inexcess of that prevailing in the upper portion of the furnace In thismanner, there is constant flow of the gas through the upper guide 24 tothe atmosphere, and ordinarily through the lower guide 24 into thefurnace chamber. Under certain circumstances there may be substantiallyno flow through the lower guide from the chamber to the furnace, howeverit is preferable to maintain the pressure within the chamber so thatlittle or no furnace gas is permitted to flow into the sealing chamber.

Steam has been found suitable for pressurizing chamber 20, since leakageof steam through the v. lower guide 24 into the furnace is not harmfulor detrimental to the structure or operation of the furnace or to thevarious parts of the gauge assembly, especially where the chamberpressure is in the order of 1 to 2 pounds per square inch greater thanthe pressure in the adjoining part of the furnace. Steam may be blownthrough pipe 25 to aid in cleaning out any solids which may havecollected in upper bushing 24, and may be blown through pipes 21similarly to clear away solids in the lower bushing. Other gases may, ofcourse, be used, and likewise other parts and combinations of parts thanthose herein illustrated may be used without departing from the spiritof this invention or the scope of the appended claims.

Having thus described the. present invention so that those skilled inthe art may be able to practice and understand the same, we state thatwhat we desire to secure by Letters Patent is defined in what isclaimed.

What is claimed is: I

1. A blast furnace stock gauge comprising a cable, a protector for thecable comprising short lengths of pipe around the cable, a tube throughwhich the cable extends, stationary guides disposed at spaced apartplaces in said tube and substantially filling the spaces between theinner surface of the tube and the outer surface of the cable protector,and means between said guides for admitting gas under pressure into theinterior of the tube.

2. A blast furnace stock gauge comprising a cable, a protector for thecable comprising a pipe through which the cable extends, a tube throughwhich the cable and pipe extend, a pair of spaced stationary guidessecured to the tube and each 4 having a portion of inside diametersubstantially less than the inside diameter of said tube but greaterthan the outside diameter of the cable protector pipe and substantiallythe same diam-.

eter as the pipe, and means between said guides for admitting gas underpressure into the interior of the tube.

3. A blast furnace stock gauge comprising a vertical tube, guidebushings at each end of the tube, a cable extending through saidbushings and tube and having a weight attached to its end within saidfurnace, a pipe communicating with the interior of said tube to supplygas under pressure to said tube, the lower bushing having a passageextending downwardly at an acute angle through the wall thereof, and apipe connected to said bushing for conducting gas under pressure intosaid passage.

4. A blast furnace stock gauge comprising a vertical tube, guidebushings at each end of the tube, a cable extending through saidbushings and tube and having a weight attached to its end within saidfurnace, a pipe communicating with the interior of said tube to supplygas under pressure to said tube, and a second pipe for gas underpressure opening at an acute angle into the said tube near the upperbushing.

5. A blast furnace stock gauge comprising a vertical tube, guidebushings at each end of the tube, a cable extending through saidbushings and tube and having a weight attached to its end within saidfurnace, a pipe communicating with the interior of said tube to supplygas under pressure to said tube, a second pipe for gas under pressureopening at an acute angle into the said tube near the upper bushing, thelower bushing having a passageway extending downwardly at an acute anglethrough the wall thereof, and a pipe connected to said bushing forconducting gas under pressure into said passageway.

JAMES ERIC HEYWORTH. EDWARD FRANCIS HARKINS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,391,504 Rankin Sept. 20, 19211,464,738 Eaton Aug. 14, 1923 1,888,605 Neely Nov. 22, 1932 1,996,784Zimmerman Apr. 9, 1935 2,322,383 Nichols June 22, 1943

